Bisq is an exchange itself but peer to peer. With shapeshift, you can't use fiat currency but with Bisq you do. You can buy and sell bitcoins and altcoins from Bisq like you would buy from sites like wall of coins, local bitcoins, etc. with privacy except I found better deals on Bisq where people are not charging a premium and sticking close to the market price. Also your bitcoins are stored on your computer wallet, and you can always recover them with the seed phrase.